1. Field of the Invention
The present invention relates to an electronic panel such as a display panel or a touch panel.
2. Description of the Related Art
In an electronic panel, such as a liquid crystal display panel or a touch panel, a transparent electrode which is formed of an Indium Tin Oxide (ITO) film is used for a region through which light passes, the drain electrode, the source electrode and the gate electrode of a thin-film transistor are formed of a metal, and metal wirings are connected to the electrodes. The metal wiring includes terminals for connection with the outside, and the terminals are covered with the ITO film in order to prevent corrosion. In detail, plated through holes are formed in an insulation film which covers the terminals of the metal wiring, and the ITO film is formed to close up the plated through holes (JP2005-236123A). Therefore, the terminals of the metal wiring are designed to electrically connect to a connection unit, such as the bump of another electrical component, via the ITO film.
In order to electrically connect the ITO film to the metal wiring, the size of the plated through hole of the insulation film should be ensured. When the size of the plated through hole is increased, it is necessary to increase the size of the metal wiring and the ITO film which covers the metal wiring. Further, a predetermined degree of length should be ensured for the interval between the connection unit, such as the bump, which is arranged on a single terminal and the ITO film which is formed on a neighboring terminal in order to prevent a short circuit. Therefore, it is difficult to have correspondence to the narrow pitch of the connection unit in a conventional structure.